Various techniques have been proposed for performing sample analysis using light emanating from objects. For example, U.S. Pat. No. 7,358,476 (Kiesel et al.) discusses a fluidic structure with a channel along which is a series of sensing components to obtain information about objects traveling within the channel, such as droplets or other objects carried by a fluid. A sensing component includes a set of cells that photosense a range of photon energies that emanate from objects. A processor receives information about objects from the sensing components and uses it to obtain spectral information. Additional techniques are described, for example, in U.S. Patent Application Publications 2008/0181827, and 2008/0183418 and U.S. Pat. Nos. 7,701,580; 7,894,068; and 8,373,860.
Also, various flow cytometry techniques have been proposed.